1. Field of the Invention
The present invention relates to a ratchet wrench, and more particularly to a ratchet wrench having a switch locking device to lock the ratchet wrench, and to prevent the ratchet wrench from being rotated or driven in different directions.
2. Description of the Prior Art
Various kinds of typical ratchet wrenches have been developed for rotating or driving fasteners, sockets, tool extensions, or the like.
For example, U.S. Pat. No. 4,987,803 to Chern, and U.S. Pat. No. 5,499,559 to Lin, and U.S. Pat. No. 6,311,584 to Chu disclose three of the typical ratchet wrenches and comprise a number of rods or rollers disposed in a socket opening of a driving head or handle, and engaged between the driving head and a driving shank.
The typical ratchet wrenches may further comprise a switching or actuating member to engage with the rollers, and to move the rollers relative to the driving head and the driving shank, in order to control the driving directions of the typical ratchet wrenches.
However, the switching or actuating member may not be locked in place, or the rollers may not be locked to the driving head, and may be moved relative to the driving head inadvertently, particularly when the typical ratchet wrenches are rotated or driven quickly by the users, such that the switching or actuating member or the rollers may be moved to different position of the driving head, and the driving direction of the typical ratchet wrenches may be changed inadvertently.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional switching or actuating members for the ratchet wrenches.
The primary objective of the present invention is to provide a ratchet wrench including a switch locking device to lock the switching or actuating member of the ratchet wrench, and to prevent the ratchet wrench from being switched to different rotating or driving directions.
In accordance with one aspect of the invention, there is provided a ratchet wrench comprising a driving head including a chamber formed therein, and including a first actuating surface and a second actuating surface, and a corner formed between the first and the second actuating surfaces of the driving head, a driven member rotatably received in the chamber of the driving head, a rod received in the chamber of the driving head, and engaged between the driving head and the driven member, and movable across the corner of the driving head, to engage with either the first actuating surface or the second actuating surface of the driving head, and means for preventing the rod from moving across the corner of the driving head, to retain the rod in engagement with either the first actuating surface or the second actuating surface of the driving head.
The preventing means includes a detent slidable into the chamber of the driving head, to engage with the rod, and to retain the rod in engagement with either the first actuating surface or the second actuating surface of the driving head. The driving head includes a groove formed therein and communicating with the chamber thereof to slidably receive the detent therein.
The preventing means further includes an actuating device slidably received in the driving head, to selectively force the detent into the chamber of the driving head and to engage with the rod. The actuating device includes a stem having a seat provided therein, to selectively engage with the detent, and thus to selectively force the detent into the chamber of the driving head and to engage with the rod.
The stem of the actuating device includes a cavity formed therein, to selectively receive the detent, and to allow the detent to be disengaged from the chamber of the driving head and to be disengaged from the rod. A spring biasing device may further be provided for biasing the seat to engage with the detent.
Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.